Ehh, you know, perhaps my taste isn't the best to try and critique the type of show because it's generally not the type I'd like but....
I found season two uninspired and boring. Half of the fun in season was was when they were introducing a character, that of course is gone in season two. Then the other half of the fun was with them setting everything up and that's gone in season two. So in the first season you had some amusing gags with Shouko, the amusing gags with Yoshii's sister, the amusing gag with Shimada's stalker girl, none of these are like high brow comedy or anything super brilliant but they work well enough the first time, once season two swung around it really had nothing new at all to add, nothing changed in anyone's relationship, no new characters were really introduced it was just more of the same but tempered by the fact it was now old hat. Only real new addition to the dynamic was a male character attracted to Yoshii and, honestly I can't remember anything else. It just wasn't memorable in any way, I can remember lots of shit from season one almost nothing from season two.
Keep in mind though that this isn't a new thing for me, I felt the same way about Sayonara Zetsubou Sensei where I felt it was at it's strongest when it was making new character introductions and once the whole cast had settled in and it switched from that angle into what's essentially a harem holding pattern it became more boring to me. Bakatest season two's the same thing, if you get a kick out of the same guy calling the same girl flat over and over again then you'll love it but to me the same gag over and over wore itself pretty damn thin. Curse of the harem structure I suppose, it's essentially doomed to stay stuck where it's at until it gets cancelled and even then that depends on the benevolence of the author as to whether it ever has a real ending or they end it in a manner that suggests it goes on as is for all of eternity.